Process for removing metals from crude petroleum oils



Sept. 23, 1952 E. A. cooNs 2,611,735

PROCESS FOR REMOVING METALS FROM CRUDE PETROLEUM OILS Filed June 21, 1947 MAKE UP ACID I2 I4 A, on. ACID TM TA I E NK HCL. l0 a I6 FLASH CHAMBER CONDENSER SETTLER 24 EVAPORATOR 22 SALTS INVENTOR EDWARD ADAMSON COONS BY l m, %mda,7nofin%maw J ATTORNEYS Patented Sept. 23, 1952 Edward Adams on' Coons, Chicago, Ill., assignor "to Sinclair Refining Com acorporation 'of Maine H, Application June 21, 1947, SerialNoQ 3 Claims. (o1. 196-39 This invention relates to improvements in the production of motor fuels from crude petroleum oil by catalytic cracking. In catalytic'cracking operations, as heretofore carried out, it has in most cases been necessary to use gas oil or other distillate as the charging stock. One important factor which has prevented theuse of reduced or top crude oils, with or without deasphalting, is that with the use of suchfe ed stocks the catalystrapidly. deteriorates. Most topped orreduced crude oils contain substantial amounts of inorganic salts, in particular sodium, calcium, and magnesium chloride, and in many cases other metallic compounds such as compounds of vanadium and nickel, the natureof which have not been fully established, and compounds of other metals. These metallic compounds are corrosive and probably responsible for the catalyst deterioration which is experienced when reduced or topped crudes are used as charging stocks to eatalytic cracking operations. The economic difference between the use of such materials as gasoil and reduced crude oil as charging stocks for cracking operations is substantial; and the present invention provides improvements which permit the use of the reduced crude oil as charging stock for catalytic cracking operations.

In accordance with the present invention, the crude oil, before or after topping or deasphalting, is treated with fiuorosulfonic acid under appropriate conditions of temperature and prespany, New York, N. v I,

idly and substantially contact isprovided.

The amountof fiuorosulfoniclacid requiredjior the removal of metal contaminants from the oil is slightly in excess "of one equivalent of 'fiuoro sulfonic acid for each equivalent of metal; and with most reduced or topped crude oils, this corresponds to a fraction of 1% of fluorosulfonic acid basedon the oil. Becausejdiflicultiesimay'been: countered in brin ing. about intimate contact of the oil with this small amount of fluorosulfonic acid, it is usually'adyantageous .toruse. a some what larger. amount, for example; 3 to5 'o'ifiluo rosulfonic acid based 'onfthe foil, recover the "ex. cess acid and recycle it until it i' s'icon'sumed. As the fiuorosulfonic' acid reactswithTthe/mtal compounds, it forms a substantially equivalent quantity of hydrogen chloride, which may be permitted to remain in the recycle stream or may be flashed off if it is desired. Retaining it in the recycle stream gives the stream an approximately constant bulb without interfering with the chemical efficiency of the reaction.

sure, with conversion of the metals present into the corresponding fiuorosulfonates substantially quantitatively. The resulting fiuorosulfonates are readily separated from the oil by filtration, settling, centrifuging or the like, and the resulting crude oil, substantially free from metal contaminants, is useful as such as the charging stock for catalytic cracking operations. The use of this as charging stock as compared with gas oil or the like results in substantial economic benefits.

The fluorosulfonic acid may be brought into contact with the metal-contaminated oil in any suitable way. Advantageously, the fluorosulfonic acid is used as the anhydrous liquid material, although it may be in the vapor phase or in aqueous form. The temperature used in the treatment may vary from about atmospheric temperature to around 400 F., advantageously above 200 F., and the pressure used should advantageously be such as to keep the anhydrous fiuorosulfonic acid liquid at the temperature selected. What is required is adequate intimate contact of the fluorosulfonic acid with the oil, because the reaction forming the metal fluorosulfonates proceeds rap- The operation may be carried out batch-wise by thoroughly mixing the oil with the fluorosulionic acid and permitting the batch to settle, separating the oil from the acid and metal salts by decantation, flashing off the hydrogen chloride if desired, and using the recovered fluorosulfonic acid from another batch until it is exhausted.

The operation may also be carried out continuously as by passing the oil and the fluorosulfonic acid to a continuous mixer such as a time tank provided with an agitator or a contacter of the type used for cold acid treating and alkylation, consisting of a vertical vessel with an open inner cylinder with a circulating pump at its bottom such that the liquid in the vessel is circulated downwardly through the inner cylinder and upwardly through the annulus between the inner cylinder and the wall of the vessel thus affording intimate admixture of immiscible liquids or liquid and gas. The eflluent mixture of oil, acid, and metal fiuorosulfonates is passed to suitable separators such as settlers, centrifuges, filters or the like to separate the oil from the acid and salt.

Apparatus suitable for such an operation is illustrated diagrammatically in the appended drawing. In the drawing, I 0 represents a time tank provided with agitating means. The oil to be treated is introduced through the inlet l2 and fluorosulfonic acid throughthe inlet M. The flu orosulfcnic acid and the oil are brought into intimate contact in the time tank, with such metal quantitatively, iiijadequate I compounds as there are in the oil being converted to the corresponding fluorosulfonates. The treated oil, in admixture with the acid and salt flows out of the outlet I6 to the settle l8, where the oil separates from the acid and the salts, and is removed by the line 20. The fluorosulfonic acid and fluorosulfonates, with the hydrogen chloride formed, are removed from the bottom of the settler l8 by the conduit 22 to the flash chamber 23, in which the hydrogen chloride is flashed oif and then supplied to the evaporating chamber 24 in which the fluorosulfonic acid is taken as an overhead product, condensed in the condenser 26 and recycled. If desired, hydrogen chloride or a part of it, may be carried away with the fiuorosulionic acid and recycled, in which case a bleed 25 is provided. Make up fiuoro'sulfonic a'cidis supplied to the line 30. Advantageously the operation is carried out at a temperature of about 200 F. Pressure is not required unless hydrogen chloride is recycled, in which case pressure is used to prevent its vaporization. The quantity'of circulatin'g fiuorosulfonic acid or a mixture of fluorosulfonic acid and hydrogen chloride is a few per cent by volume based on the oil, for example, 3 to I claim:

l. In aprocess involving pretreatment of crude petroleum oils containing metal compounds and subsequent use of the pretreated crude petroleum oils as a charging stock in a'catalytic cracking opei'ation, the improvement which comprises jsubjecting the crude petroleum oils in the pretreatin'g operation and prior to bringing theoil into contact with the cracking "catalyst into intimate admixture with fluorosulfonic acid whereby the metal compounds initially present in the crude petroleum oils react with the fiuorosulfonlc acid to form the corresponding fluorosulfonates, and separating the resulting fiuorosulfonates from the oil.

2. In a process as defined in claim 1 the improvement consisting of conducting the -pretreat ing operation by admixing anhydrous liquid fluorosulfonic acid with the crude petroleum oils un der a superatmospheric pressure sufficient to maintain the fluorosulfonic acid in liquid phase.

3. In a process as defined in claim 1 the im-' provement consisting of admixing fluorosulfonic acid with the crude petroleum oil during the pretreating operation in an amount substantially in excess of that required to react with the meta compounds present in the oil.

EDWARD ADAMSON COONS.

REFERENCES CITED The following references are of record inthei file of'this pate'nt:'

- UNITED STATES PATENTS Number Name Date 1,833,331 Park Nov. 24, 1931 1,984,903 Wagner Dec.'18,'l934 2,203,470 Pier et a1. June', 1940 2,206,500 Q Fischer etal. July 2,1940 2,428,753 Linn Oct. 7,1947 2,450,588 Evering et al Oct. 5,1948

FOREIGN PATENTS Number Country Date 309,042 Great Britain Sept. 3,1930 

1. IN A PROCESS INVOLVING PRETREATMENT OF CRUDE PETROLEUM OILS CONTAINING METAL COMPOUNDS AND SUBSEQUENT USE OF THE PRETREATED CRUDE PETROLEUM OILS AS A CHARGING STOCK IN A CATALYTIC CRACKING OPERATION, THE IMPROVEMENT WHICH COMPRISES SUBJECTING THE CRUDE PETROLEUM OILS IN THE PRETREATING OPERATION AND PRIOR TO BRINGING THE OIL INTO CONTACT WITH THE CRACKING CATALYST INTO INTIMATE ADMIXTURE WITH FLUOROSULFONIC ACID WHEREBY THE 